Apparatus and Method for a Combination of Ablative and Nonablative Dermatological Treatment

Abstract

The invention describes a treatment for skin wherein a pattern of holes is ablated in a selected region of skin tissue using an optical source. Substantially nonablative energy is delivered to the selected region to at least two holes in the pattern to thermally heat a target in or just beneath the skin, such as hair follicles, sebaceous glands, or subcutaneous fat. The invention may further be improved by adding a feedback mechanism that adapts the nonablative energy in response to a measurement enabled by the ablation of holes. The apparatus may include a positional sensor to provide additional dosage control, particularly when the inventive method is used with a continuously movable handpiece.

1 . A method of dermatological treatment comprising the steps of
 directing optical energy from an optical source to a selected region of skin, the optical energy ablating a pattern of discrete holes in epidermal and dermal tissue in the selected region of skin; and   delivering at least one pulse of optical energy from the optical source to at least two of the discrete holes, wherein the pulse of optical energy is substantially nonablative.   
     
     
         2 . A method of  claim 1 , wherein the delivering step causes treatment of at least one lipid-rich target. 
     
     
         3 . A method of  claim 1 , wherein the optical source includes exactly one laser, the directing step comprises directing optical energy from the laser to the selected region of skin, and the delivering step comprises delivering at least one pulse of optical energy from the laser to at least two of the discrete holes. 
     
     
         4 . A method of  claim 1 , wherein the optical source includes two or more lasers, the directing step comprises directing optical energy from one of the lasers to the selected region of skin, and the delivering step comprises delivering at least one pulse of optical energy from a different one of the lasers to at least two of the discrete holes. 
     
     
         5 . A method of  claim 1 , further comprising the steps of
 evaluating at least a portion of tissue from the selected region in connection with the ablating step; and   controlling the delivering step in response to a result of the evaluating step.   
     
     
         6 . A method of  claim 5 , wherein the evaluating step comprises the step of, in connection with the ablating step, detecting a presence or absence of at least one of hair follicles, hair bulge cells, and vascular tissue. 
     
     
         7 . A method of  claim 5 , wherein the evaluating step comprises the step of, in connection with the ablating step, detecting a presence or absence of lipid-rich tissue. 
     
     
         8 . A method of  claim 5 , wherein the evaluating step comprises measuring a characteristic of a portion of tissue that contains at least part of the ablated tissue. 
     
     
         9 . A method of  claim 8 , wherein the measured characteristic comprises an ablation rate. 
     
     
         10 . A method of  claim 8 , wherein the measured characteristic comprises at least one of a scattering property and an absorption property of the portion of tissue for at least one optical wavelength. 
     
     
         11 . A method of  claim 8 , wherein the measured characteristic comprises an optical absorption or scattering of the portion of tissue at least two wavelengths. 
     
     
         12 . A method of  claim 5 , wherein the evaluating step comprises detecting an acoustic signal generated as a result of the ablating step. 
     
     
         13 . A method of  claim 5 , wherein the controlling step comprises the step of reducing the energy delivery rate of the laser. 
     
     
         14 . A method of  claim 13 , wherein the reducing step is performed in response to identification of lipid-rich tissue during the evaluating step. 
     
     
         15 . A method of  claim 5 , wherein the controlling step comprises the step of changing the wavelength of the laser in response to identification of lipid-rich tissue during the evaluating step. 
     
     
         16 . A method of  claim 5 , wherein the controlling step comprises delivering at least one pulse of optical energy to a hole created during the ablation step. 
     
     
         17 . A method of  claim 1 , wherein the ablating step comprises the step of directing a laser beam to the selected region to heat water in the selected region. 
     
     
         18 . A method of  claim 17 , wherein at least two discrete holes are created in a pattern corresponding to the optical intensity profile of the laser beam. 
     
     
         19 . A method of  claim 17 , wherein the controlling step further comprises the step of delivering a beam from an optical source comprising at least one of the laser and a second laser to at least two of the holes to cause treatment of at least one lipid rich target. 
     
     
         20 . A method of  claim 1 , wherein the density of holes is 100-10,000 per square centimeter in the selected region. 
     
     
         21 . A method of  claim 20 , wherein the density of holes is 1000-2000 per square centimeter in the selected region. 
     
     
         22 . A method of  claim 1 , further comprising the step of scanning the location of the at least one pulse of optical energy across the skin. 
     
     
         23 . A method of  claim 1 , further comprising focusing the at least one pulse of optical energy using an optical lens array. 
     
     
         24 . A method of  claim 1 , wherein at least one of the holes has a depth of 0.5-6 mm and a diameter of 0.2-2.0 mm. 
     
     
         25 . An apparatus for dermatological treatment comprising:
 an optical source configured to produce ablative optical energy and nonablative optical energy; and   a delivery system that delivers the ablative optical energy to multiple discrete locations at a selected region of skin to ablate a pattern of discrete holes in the selected region and that further delivers the nonablative energy to at least two of the discrete holes.   
     
     
         26 . An apparatus of  claim 25 , wherein the optical source includes at least one laser for producing the ablative optical energy and another laser for producing the nonablative optical energy. 
     
     
         27 . An apparatus of  claim 25 , wherein the optical source comprises at least one of a CO 2  laser, a thulium-doped fiber laser, an Er:YAG laser, and a holmium laser. 
     
     
         28 . An apparatus of  claim 27 , wherein the optical source comprises a thulium-doped fiber laser that is configured to be tunable. 
     
     
         29 . An apparatus of  claim 27 , wherein the optical source comprises a CO 2  laser and a Raman-shifted fiber laser. 
     
     
         30 . An apparatus of  claim 27 , wherein the optical source comprises a CO 2  laser and at least one of an erbium-doped fiber laser and an erbium-doped fiber amplifier. 
     
     
         31 . An apparatus of  claim 25 , wherein the optical source comprises a Raman-shifting element. 
     
     
         32 . An apparatus of  claim 25 , wherein the optical source emits a normeglible amount of energy at an infrared fat-selective wavelength. 
     
     
         33 . An apparatus of  claim 32 , wherein the optical source emits a normeglible amount of energy at an infrared water absorbed wavelength. 
     
     
         34 . An apparatus of  claim 25 , further comprising a positional sensor that measures at least one of the relative position, relative velocity, relative speed, and relative acceleration between the handpiece and the selected region. 
     
     
         35 . An apparatus of  claim 34 , wherein the controller is further configured to receive data from the positional sensor and controls at least one parameter of the optical source that affect dermatological treatment in response to data received from the positional sensor. 
     
     
         36 . An apparatus of  claim 25 , wherein the delivery system comprises an optical scanner. 
     
     
         37 . An apparatus of  claim 25 , wherein the delivery system comprises an optical lens array. 
     
     
         38 . An apparatus of  claim 25 , wherein the delivery system comprises a patterned mask.